ETRA HYDRO Dam Oil-Filled Power Transformer

Description

KOLEKTOR ETRA supplies oil-filled power transformers up to 500 MVA and voltages up to 420 kV.

For step-up and step-down power transformers, as well as production transformers in hydroelectric stations, we prioritize reducing noise levels and ensuring very low load and no-load losses. We carefully dimension conductors and insulating materials to handle production peaks from hydroelectric turbines and mitigate overheating caused by sunshine or confined areas.

Our low levels of no-load and on-load losses are achieved using the highest quality materials and advanced technological know-how, which KOLEKTOR ETRA® possesses. This enables us to offer transformers that minimize lifecycle costs, both on-load and off-load. The noise levels of our transformers are low enough to significantly reduce the cost of building noise mitigation devices.

For hydroelectric stations applications, we offer transformers equipped with cooling systems such as ONAN, ONAF, ODAF, OFAF, ODWF, or OFWF.

With our US-ISATION program launched in 2021 in partnership with NORTHBRIT and KOLEKTOR ETRA® Group, you benefit from comprehensive service and technical support in America. From the sales department to the design office, including factory project management and site project management, our US-based service partners ensure seamless execution and support.

Thanks to NORTHBRIT experts based in Connecticut and our US service partners, we offer essential services for your substation projects, including:

• Measurement and 3D scanning of your transformer box for a customized design tailored to your constraints
• Reconnaissance and “last mile” marking
• Transport and on-site delivery
• Transformer unloading via rigging or craning
• Project management with service companies for assembly, on-site filling, and oil treatment
• Site acceptance testing and commissioning
• After-sales services and technical support
• Creation of a temporary storage area with flexible berms TRFLEX-ECO or TFLFLEX-REFOR, or watertight concrete with drainage skid PETRO PIPE
• Replacement of remote conservatories and installation of safe maintenance platforms with crutch ladders
• Removal of contaminated pebbles from old transformer pits, cleaning, pit lining, installation of fire-suffocating covers for STONEQUENCH-LHD transformers, and installation of SPI rainwater drainage systems at the bottom of retention pits
• Room-temperature galvannealing of metal structures and high and medium-voltage gantries with our unique galvanic coating GALVAGRID
• Protection of low and medium voltage systems from animal and plant intrusion with MIDSUN AVIFAUNE plastic-free, heat-free, glue-free protective covers
• Installation of SANERVIB SP high-performance anti-vibration systems

Additional information

Generic Design Data

Note: Specifications may vary based on design requirements.

Magnetic Laminations:

• Conventional Oriented C.G.O. Class Laminations
• HI-B High Magnetic Orientation Steel Sheets
• Laser-Treated Magnetic Laminations

The magnetic core, available with 2, 3, or 5 legs, is constructed by stacking individual steel sheets. Core laminations are securely held by heat-shrink polyglass strips and anti-magnetic steel clamps, with the lower yoke and limbs varnish-glued to minimize oscillations and vibrations caused by magnetostriction forces.

The frame, comprising the clamp and legs, is fixed around the magnetic core to ensure safe transportation and resistance to electromagnetic short-circuit forces.

Windings:

• Made from high-purity electrolytic copper, Cu-ETP
• Single- or multi-layer windings for phase currents up to 1000 A and rated voltages up to 72.5 kV
• Disc windings (helical, continuous, or interlaced) for higher voltage classes

Specific electrical conductivity: 58 Sm/mm²

Conventional yield strength (RP0.2) of conductors: 90 to 160 N/mm²

Thermal Insulation Classes:

• Enamel Insulation (PVA), Thermal Class E (120°C), IEC 60317-0-2 compliant
• 5A2-1M3 Paper Insulation, Thermal Class A (105°C), IEC 554-3-5 compliant
• Thermally Improved Paper Insulation 5B1-2M3, Thermal Class E (120°C), IEC 554-3-5 compliant

Cooling System: The transformers are equipped with efficient cooling systems, designed and tested for continuous operation within specified temperature limits. If there are no overload requirements, the cooling system adheres to IEC 60076-7 standards. The system includes radiators and various types of oil coolers or heat exchangers, which can be separated from the reservoir for quick installation or dismantling. The system can also be located in separate installations for better heat dissipation, equipped with pumps for faster oil circulation. Only OF and OD types are used.

Heritage and Innovation: Our archives contain over 4000 different models, many of which are actively used in our service activities. This extensive repository represents a unique blend of tradition, innovation, experience, and excellence.

Testing and Standards: KOLEKTOR ETRA conducts all routine and special tests required by international industry standards, including IEC, EN, and ANSI:

• IEC 60076: Temperature rise, insulation levels, dielectric tests, short-circuit withstand, and application guide.
• IEC 60354: Loading guide for oil-immersed power transformers.
• NF C13-200: Design and implementation rules for electrical installations with nominal voltages >1 kV and ≤245 kV in AC, 50 Hz, and 60 Hz.

Assembly Inspections: Each core, winding, reservoir, and other parts undergo mechanical and electrical inspection prior to assembly. During assembly, the following operations are performed:

• Voltage ratio interphase measurement
• Insulation resistance measurement
• Measurement of short-circuit loss before the drying process
• Drying process and transformer oil monitoring

With the support of our NORTHBRIT team and US service partners, we are fully equipped to assist you with your project and site support needs.

Contact Us: Reach out with your site information and project requirements.